There are numerous of reasons to monitor the health and/or activity of a person occupying a bed. For example a significant cause of death in infants (birth to about 2 years) is “Crib Death” or Sudden Infant Death Syndrome (SIDS). Medical authorities generally agree that some infants simply stop breathing during sleep (apnea) or their heart rates fall dangerously low (bradycardia) and that death from these conditions can be prevented if the condition is detected and help is provided within a short time (one or two minutes) by trained personnel or parents. □ □ Apnea monitors already exist, but their cost creates an affordability problem that limits their use. Also, the existing monitors tend to be unreliable, typically having high false positive rates. Also, existing monitors are obtrusive and difficult to use because the subject must wear a belt or other device connected to the monitor. This further limits their use, and it would accordingly be desirable to have a bed-monitoring device which is both inexpensive and reliable in providing information relating to breaths, heartbeats, breathing rate, or heart rate of a monitored person.
Also in various types of care, such as medical service, geriatric care, mental health care services, etc. . . . , continuous surveillance of patients that for different reasons cannot be permitted to leave the bed single-handedly is required. For instance, it may occur that mentally deranged patients, above all in the night-time, get up from their beds and wander about in the care institution in question or even abscond from the same.
In order to address the aforementioned desire, it is known to use sensors coupled to a mattress for monitoring a bed occupant. For example PCT Publication WO 2004/006768 provides a bed occupant monitoring system comprising a plurality of optical fibres with their ends within a sheet of foam material. In order to provide a reliable output, the elasticity of the support material must be substantially the same as the elasticity of the foam material incorporating the optical fibres (see claim 10 of WO 2004/006768), posing serious limitations to the overall applicability of the bed monitoring device described therein.
PCT Publication WO 93/11553 generally describes a motion monitoring device based on a single- or multimode-optical fibre illuminated by a coherent or partially coherent light source but is silent about an optimal way of coupling such a system to a mattress.
PCT publication WO2006/046928 provides an occupant monitoring and alert system consisting of a plurality of sensor located within a mattress and characterized in consisting of an upper and lower plate of electrically conductive material and an intermediate compressible layer.
U.S. Pat. No. 6,498,652 also provide a fiber optic monitoring system for detecting vital signs of a patient, with an apparent general applicability in monitoring the health and/or activity of a person occupying a bed, but is again silent about an optimal way of coupling such a system to a mattress.
EP 2 412 310 also discloses a bed-monitoring device comprising a GI quartz-based optical fiber knitted into a cloth. As shown in FIG. 5, and explained in the description, compared to an optical fiber made from a plastic material, a GI-quartz based optical fiber provides the best measurement, with a remarkable sensitivity, hardly influenced by electrical noise or static electricity resulting from friction or the like. To live up to the required rigidity in use, and as evident from the adhesive used in the examples on file, the quartz optical fiber must be fixed and immobilized with respect to substrate support material. This limits its application in adjustable beds requiring a high degree of adaptability of the optical fiber per se.
JP 2002 219108 an optical ballistocardiograph has been described. In said device an optical fiber is anchored between rigid upper and lower plates. A stress integrator is further present to concentrate the stress that affects the optical fiber. For the same reasons as mentioned for EP 2 412 310 above, such a rigid structure has clear disadvantages when used in a sleeping environment, and accordingly fails to provide a solution to the desired hidden integration of an optical fiber in a bed occupant monitoring and alert system, in particular when applied in adjustable beds, such as for example used in the (health) care sector.
JP 2007 144070 also provides equipment for detecting pressure changes in a bed from a sleeping person, said equipment using an optical fiber bedded between the upside of the bedclothes and said person. With reference to [010] of said application, the optical fiber being fixed with adhesive tape. Compared to the present invention, the optical fiber is not well integrated into the mattress cover and fails to provide the breakpoints, that together with the further characteristics on the integration of the fiber provide an optimised integration in a sleeping environment.
It is accordingly an object of the present invention to provide a method for coupling a fiber optic monitoring system, in particular a synthetic fiber optic monitoring system to a mattress assuring a reliable method in monitoring bodily activity of a person and in particular vital signs such as respiration, cardiac activity and body's physical movement, including the presence, absence, step in/out or even falling out of a person using a sleeping environment such as a bed; mattress; top-mattress, bedding such as mattress covers, and pillow covers; a pad; a futon and the like. As will be further detailed hereinafter, the application of the optical fiber in an overlocked bag surrounded by support members comprising pressure points at discrete locations, yielded the desired reliable and hidden integration of a bed monitoring device in a sleeping environment.
Based on the monitoring of bodily activity, the device of the present invention further allows determining sleep comfort and sleeping position of the user, and accordingly provides a valuable R&D tool to manufactures of sleeping articles like beds, mattresses, futons and the like; but also in counselling consumers when buying sleeping articles under professional guidance.
These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings.
The dimensions (in cm) given throughout the drawings are given as by way of example and not limiting the invention.